1. Field of the Invention
The present invention relates to a Rankine cycle system and a method of controlling the same, and more particularly, to a Rankine cycle system which generates electricity by using heat as an energy source, in which a conventional pump for carrying a working fluid is not used, thereby reducing the cost of manufacturing the Rankine cycle system, saving the electric power consumed to operate the pump and therefore obtaining a greater output of power, and in which a control system is used to automatically operate the Rankine cycle system, thereby enabling to stably operate the Rankine cycle system even though a heat source is intermittently supplied, and a method of controlling the same.
2. Description of the Related Art
Generally, as illustrated in FIG. 1, when a working fluid is heated in an evaporator 1 by using heat supplied from a heat source, the working fluid turns into a gas at a high temperature and high pressure, to flow into an expander 2. During the process that the working fluid expands at a low pressure state in the expander 2, the Rankine cycle generates electricity, using a generator 3.
The working fluid discharged from the expander 2 enters a condenser 4 and is condensed by heat-exchange with cooling water. The working fluid condensed in the condenser 4 becomes a liquid at a low temperature and low pressure in a lower part of the condenser 4. After the working fluid in the liquid state becomes a low temperature and high pressure state while passing through a working fluid pump 5, it again flows into the evaporator 1, so that the above-described processes are repeated.
However, in the aforementioned conventional Rankine cycle, since the expensive working fluid pump is needed and a lot of power is consumed to operate the working fluid pump, the output of the cycle is decreased and therefore the efficiency of the cycle is decreased.